Sally is 4 years older than Tim. Together, the sum of their ages is 20. How old is each person?

1 Answer
Nov 17, 2015

Tim is #8# and Sally is #12#.

Explanation:

You can represent each person's age using variables. Let #x# = Tim's age. Because Sally is 4 years older than Tim, you can represent her age as #4 + x#.

Sally's Age = #4 + x#
Tim's Age = #x#

The sum of their ages is #20#, so add both expressions.

#(4+x) + (x) = 20#.
#4 + 2x = 20#
#2x = 16#
#x = 8#

#x# represents Tim's age, so Tim is #8#. Sally is #4# years older, so Sally is #12#.